I would personally bet on payments, insurance, fashion, and banking over space, robotics, desktop manufacturing, and augmented reality. The former are things that virtually everybody does as part of their daily life. The latter are things that sound very sexy and have had some big wins in specific industries, but aren't related to what people do day-to-day. When pitting reality against dreams, reality usually tends to win out.
The same could have been said about computers fifty years ago. No one used computer as part of their daily life when computers filled entire rooms. I'm glad Steve Jobs and Bill Gates didn't get into insurance.
50 years ago (well, 60-70), a computer was a person - it was a job description. In world war 2 and the decade after, there would be rooms full of young women (they were usually women, because men were off at war) with Marchant calculators computing artillery trajectories and breaking Nazi codes. The first computers were invented to automate this job description. They were not some big pie-in-the-sky research project, they were a very pragmatic (and clumsy) attempt to mechanize away a very labor-intensive process so those workers could be freed up to do other work.
Many of the more successful startups recently follow the same pattern: they work to eliminate one job description. Zillow = real estate agents, Square = cashiers, LendUp = bankers, Yelp = food critics, AirBnB = hoteliers. Heck, the initial apps that made the personal computer successful also had that pattern: Visicalc = accountants, Adobe = print shops. Jobs and Gates got rich because they controlled the infrastructure that these businesses built upon, but the folks who built those apps also got fairly rich as well. Heck, Bill Gates's first programming job was writing a payroll program, and his first business venture was software for traffic counters.
